1. Field of the Invention
The invention relates to a device for manipulating and removing a die, a discard and a closing plate or disk of different diameters and discard thicknesses from the bore of the billet carrier and from the press itself, after extrusion in an indirect metal extrusion press.
2. Description of the Prior Art
U.S. patent application Ser. No. 356,798, filed Mar. 10, 1982 discloses a removal arm, which can be swung into the press axis and the free end of which carries a one-component or two-component holding sleeve for holding the closing plate, the billet discard and the die. The sleeve end facing the closing ram supports a base plate, and the sleeve is used to strip the tools from the bore of the billet receiver of an indirect metal extrusion press. In the case of the two-component embodiment the sleeve is divided transversely to the press axis, and the sleeve part holding the discard and the closing plate is arranged so as to be either pivotable or displaceable transversely to the press axis on the arm, while the other sleeve part, rigid on the arm, is intended to receive the die.
When shearing off the discard (i.e. the unextruded butt end of the extruded billet) from the die by means of a radially acting shearing device on the billet receiver holder, the discard and the closing plate remain in the sleeve part which is movable transversely to the press axis and is provided with the base plate, and must be axially ejected outside the press.
If the holding sleeve is formed as a single component, it comprises an opening transverse to the sleeve axis and which corresponds to the diameter of the closing plate and at least the thickness of the discard and the closing plate. The discard with the attached closing plate can then be removed from the die through this opening by means of the shearing device. A catching device may be provided beneath the opening.
The mode of operation of the indirect metal extrusion press requires controlled shearing of the discard by a shearing device fitted on the billet carrier holder. After the die, the discard and the closing plate have been ejected from the bore of the billet carrier with the aid of the press force the discard is shorn off from the pressed material in front of the die. In this connection the die must be held and positioned in such a way outside the billet carrier that the discard with the closing plate can be shorn off in a troublefree manner. Since, however, the billet carrier must be operated at temperatures between 300.degree. and 500.degree. C., definite positioning of the die holder and the die presents problems. It is therefore not always possible to ensure that the centre of the holding sleeve of the removal arm matches the press axis. In addition, reliability of operation and a minimum of manipulation are necessary during the automatic operating cycles.